Many recent pollution prevention efforts in the pulp and paper industry have focused on getting rid of the use of chlorine for bleaching, a process which helps to increase the brightness of the paper. Elemental chlorine (that is, pure chlorine) or chlorine dioxide is generally used for bleaching but, in the process, large amounts of chlorinated pollutants such as dioxins -- a persistent organic pollutant with very high cancer-causing potential -- are released into the water. Hence, there is an increasing trend worldwide to reduce the use of both elemental chlorine and chemicals containing chlorine.
Two bleaching processes, which are increasingly being adopted by Western nations are elemental chlorine free (
ecf ) bleaching and total chlorine free
(tcf ) bleaching. However, to make investment in environment-friendly bleaching processes more economically feasible, Indian companies will have to expand their capacity to take into account the economies of scale.
In industrialised countries, most of the firms are large ones. But, in India, they are mostly small or medium-sized. Hence, there is little scope for investment in pollution prevention technologies. But even if we ignore these mills in India, not one of the larger mills is anywhere near adopting truly environment-friendly technologies, or even replacing the more dangerous elemental chlorine with chlorine dioxide. Only a few mills are producing chlorine dioxide in order to partially replace use of elemental chlorine.